The present invention relates to the field of protection against lightning for use in high temperature environments. A particular but non-exclusive field of the present invention is that of providing protection against lightning for hot parts present in thrusters for space launchers, tactical launchers, etc., or in aeroengines.
The thrusters of launchers of that type or the afterbody parts of aeroengines are liable to be struck by lightning in flight. When a part that is struck by lightning is made of a material that is not conductive, such as a composite material, or when it is covered in a dielectric material, the structure of the part may be severely damaged by the impulse and continuous components of the electric arc created by the lightning.
Several techniques already exist for providing protection against lightning, with the main purpose of encouraging the lightning current to flow through the protection instead of through the structure for protecting and to increase rapidly the size of the impact point of the lightning arc so as to reduce thermal and mechanical stresses.
Among existing solutions, there are to be found lightning protective coatings that are constituted by:                metallic fabrics fastened to the surface of the part for protecting;        expanded metal grids made from a metal sheet that has been slotted and stretched in order to form a grid that is likewise fastened to the surface of the part to be protected;        conductive layers made by depositing metal particles, e.g. nickel particles, on the surface of the part to be protected in order to increase its conductivity; and        metallic fibers woven directly in the fiber texture of the reinforcement of the composite material part for protecting so as to form a multitude of small points at the surface of the part suitable for dispersing the impact point of the lightning arc.        
Nevertheless, those various coatings present certain drawbacks, and the major drawback is poor ability to withstand high temperatures. In addition, some of those coatings are difficult to put into place on structures that are complex in shape.
Those solutions also present the drawback of being difficult to repair.